I know it says that Mr. S was SW agent. However, I assume that SW was a landowner, that is where his income came from. Why did he have no steward to advise him? Or was Mr. S his steward? I seem to recall from the Annotated Version of P&P that the term "steward" was becoming obsolete, but I don't know if "agent" was the term that replaced it. Old Mr. Wickham was an attorney, and was Old Mr. Darcy's steward, so perhaps that is it...